Motion-picture apparatus



July 20, 1948. PARRY 2,445,689

IQTION PICTURE APPARATUS Filed Dec. 19, 1945 3 Shoots-Sheet 1 44 I" 322s mmvron.

28 35 ROBERT D. PARRY ATTORNEY am w. 1/1, I!

July 20, 1948. R. D. PARRY 2,445,689

MOTION PICTURE APPARATUS Filed Dec. 19, 1945 3 Sheets-Sheet 2 V. as IINVEN TOR. ROBERT D. FARRY ATWRNEV July 20, 1948. R. D. PARRY 2,445,539

MOTION PICTURE APPARATUS Filed Dec. 19, 1945 s Sheets-Sheet s INVENTOR.

ROBERT D. PARRY ATTORNEY Patented July 20, 1948 I MOTION-PICTUREAPPARATUS Robert D. Parry, Cincinnati, Ohio, assignor to Dayton AcmeCo., CincinnatLOhio, a corpora tlon of Ohio Application December 19,1945, Serial No. 835,880

This invention relates to motion picture projectors, and moreparticularly to mechanism for restoring the lower film loop'onprojectors using a claw-type intermittent feed mechanism. The lower filmloop is sometimes lost due to defective apertures in the film orincorrect engagement of the intermittent claw with the film. Such lossof the lower film loop causes a jumpy picture and also affects the soundmechanism. It is, therefore, desirable to provide means in connectionwith the projector whereby the lower film loop can be restored withoutstopping the projec tor or interfering with the showing of the picture.

The object of my invention is to provide means tor increasing the speedof the intermittent mechanism without affecting the speed of the feedsprockets. Y

' -her object is to provide means extende the projector whereby theoperator mtly effect a speeding up of the interttent mechanism torestore the loop.

' ther object is to provide novel means for i: re ing the speed of theintermittent mechainv-ention will he further readily understood from thefollowing description and claims and irom the drawings. in which latter:

Fi is a side view of a portion or a projector, ncorporatingimprovements.

Fig. 2 a horizontal section view, taken in the grime of the line 2-2 ofFig. 4.

Fig. 3 is a vertical section, taken in the plane of the line 3-3 of Fig.4.

Fig. l is a vertical section, viewing the mechanism from the rear faceof the projector, taken in the plane of the line 4-4 of Fig. 3.

Fig. 5 is a section similar to Fig. 4, showing the lmob depressed forspeeding up the intermittent mechanism.

Fig. 6 is a sectional view similar to Fig. 4, showing a modification ofthe driving mechanism.

Fig. '7 is a companion sectional view to Fig. 6, with the knob depressedfor increasing the speed of the intermittent mechanism, and;

Fig. 8 is a detail section, taken in the plane of the line 8-3 of Fig.7.

I have shown my improved mechanism in connection with a projector ll,having an upper feed sprocket 12, a gate or pressure pad l3, and a lowerfeed sprocket M, an intermittent mechanism l5 intermittently feeds thefilm l6 one frame at a time past the projection aperture. It isessential that a loop I! and a loop l8 be maintained between theconstant feed sprockets l2 and i4 and the intermittent mechanism l5 to 4Claims. iGL 8818.4)

permit the film to stop at the aperture while the shutter is open. Afterthe film leaves the sprocket I4, it travels over a sound drum, not shownbut well-known in the art. and it is essential that the film moves at aconstant speed over the sound drum to produce good quality sound. If thefilm has defective apertures, or for any other reason the claw of theintermittent mechanism does not progress the film the lower loop i8 willdisappear and the film will then be jerked, interfering with goodprojection and at times causing the film to break. As the lower loopdisappears, the upper loop will increase in size and my invention isdirected to mechanism for restoring the lower loop IS without affectingthe ieeding of the film over the sprockets i2 and M.

in the projector exemplified in the drawings,

the mechanism is driven from a shaft to which receives its power from asuitable motor. Gears 2! and 22 impart rotation to gears 23 and 24 fordriving the upper sprocket i2 and the lower sprocket i4 at a constantspeed. A cross-shaft as is suitably journalled on the frame of themachine and is provided with a spiral gear 23 meshing with a spiral gear2'! on the shaft 20. A collar 23 is secured to the shaft 25. A shaft isin axial alignment with the shaft 25 has a member 30 fixed thereto witha spring clutch 3i interposed between the collar 28 and the member tofor normally rotating the shafts 25 and 29 in unison. A spiral gear 32is attached to the shaft 29 and meshes with a spiral gear 33 secured tothe shaft 34 for driving the intermittent mechanism 95. The shutter 35is also mounted on the shaft 29. A collar 36 is received aboutthermember 30 and is provided with pins 31 received in enlargedapertures 38 in the collar 3-8 for forming a driving connection betweenthe collar 28 and the collar 36. The collar 36 is normally maintained ina concentric position about the member 30 by means of an endwise movablemember 39 provided with a tapered engaging face 40 and being urged intoengagement with the collar 36 by means of a spring washer 4|.

Projectors of this type are usually enclosed in a suitable case, the toppanel of which is indicated at 42. In order to provide means for movingthe collar 36 transversely to the member 30, I provide a guide 43secured to the case 42 and carrying a spring pressed yoke 44. A spring45 received about the guide rod 46 of the yoke, normally maintains theyoke in an UP position. The yoke is provided with a pair of rollers 41engaging the collar 35 and the upper end of the rod it is provided witha knob 48.

In the normal operation of the projector, the parts are in the positionshown in Figs. 1 to 4, inclusive; however, should the lower film loopdisappear, the operator merely presses down on the knob 58 to theposition shown in Fig. 5 for engaging the collar 36 with the member 30,causing the collar 36 to drive the member it at an increased speed forcausing a speeding up of the shutter and the intermittent mechanism torestore the lower film loop it without interfering with the continuedprojection of the picture being shown. Upon release of theknob 65% themovable member 39! under the urging of the spring washer it returns thecollar 36 to normal position.

In the modification shown in Figs. 6 to 8 inclusive, the member isprovided with gear teeth 50 and the collar is provided with gear teeth5i. Thus, when the collar 36 is depressed, the teeth it will engage theteeth 50 for increasing the speed of the shaft 29.

' It will be apparent from the foregoing description that I have deviseda simple positive means for restoring the lower film loop withoutaffecting the operation of the projector.

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent is:

1. In a motion picture projector having an upper constant speed filmfeeding sprocket, a lower constant speed film feeding sprocket, anintermittent film feeding mechanism interposed between said feedsprockets operating with a free loop between each of said feed sprocketsand the intermittent mechanism, means for increasing the speed of theintermittent mechanism for restoring the lower film loop, comprising adrive shaft, a member fixed to said shaft, a floating collar havingdriving connection with said member, a second shaft in axial alignmentwith said first-named shaft, a member fixed to said second shaft andhaving frictional means interposed between said last-named member andsaid member fixed to said first-named shaft for normal driving of saidsecond shaft, and means for transversely shifting said collar to form adrive between said collar and the member fixed to said second shaft forincreasing the speed of said second shaft.

2. In a motion picture projector having an upper constant speed filmfeeding sprocket, a lower constant speed film feeding sprocket, anintermittent film feeding mechanism interposed between said feedsprockets operating with a free loop between each of said feed sprocketsand the intermittent mechanism, means for increasing the speed of theintermittent mechanism for restoring the lower film loop, comprising adrive shaft, a member fixed to said shaft, a floating collar havingdriving connection with said member, a second shaft in axial alignmentwith said first-named shaft, a member fixed to said second shaft andhaving frictional means interposed between said last-named member andsaid member fixed to said first-named shaft for normal driving of saidsecond shaft, and means for transversely shifting said collar to form afriction drive between said collar and the member fixed to said secondshaft for. increasing the speed of said second shaft.

3. In a motion picture projector having an upper constant speed filmfeeding sprocket, a lower constant speed film feeding sprocket, anintermittent film feeding mechanism interposed between said feedsprockets operating with a free loop between each of said feed sprocketsand the intermittent mechanism, means for increasing the speed of theintermittent mechanism for restoring the lower film loop, comprising adrive shaft, a member fixed to said shaft, a floating collar .havingdriving connection with said memher, a second shaft in axial alignmentwith said first-named shaft, a member fixed to said second shaft andhaving frictional means interposed between said last-named member andsaid member fixed to said first-named shaft for normal driving of saidsecond shaft, and means for transversely shifting said collar to form agear drive between said collar and the member fixed to said second shaftfor increasing the speed of said second shaft.

4. In a motion picture projector having an upper constant speed filmfeeding sprocket, a lower constant speed film feeding sprocket, anintermittent film feeding mechanism interposed be-' tween said feedsprockets operating with a free loop between each of said feed sprocketsand the intermittent mechanism, means for increasing the speed of theintermittent mechanism for restoring the lower film loop, comprising adrive shaft, a member fixed to said shaft, a floating collar havingdriving connection with said member, a second shaft in axial alignmentwith said firstnamed shaft, a member fixed to said second shaft andhaving frictional means interposed between said last-named member andsaid member fixed to said first-named shaft for normal driving of saidsecond shaft, means for shifting said collar to form a drive betweensaid collar and the member fixed to said second shaft for increasing thspeed of said second shaft, and means for normally maintaining saidcollar concentric with said first-named member.

ROBERT D. PARRY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

